A +B=C

[Igobyliz]

Hi,

I am trying to create a formula table. For example,

If We need 500 gallons of Blue.

Chemical A it takes 300 gallons and chemical B take 200 gallons to make 500 gallons Blue.
How do we tell the spreadsheet we need 500 gallons of Blue and the spreadsheet tells us how much of Chemical A and how much of Chemical B.

[#2]

IF the ratio of chemical A: chemical B is 3:2 then if the desired amount of Blue is entered in A1 then the formula for chemical A is =A1*3/5 and the formula for chemical B is =A1*2/5